However Federal Parliament, fearing a political backlash against workers on award wages, attempted to reverse these cuts ahead of the busy Christmas shopping period.

Industry leaders decried the backflip, saying it will increase the burden on business owners to work longer hours and reduce headcount in order to balance the books.

“If Sunday Penalty Rates are increased, many families will be taking a big cut this Christmas as small business will be forced to have fewer staff, work longer hours themselves, and let go hard working employees,” said Adam Joy, head of the Australian Lottery and Newsagents Association.

“The budget that retailers have to pay staff isn’t changing, and can’t change, so less people will be able to be paid.”

Mr Joy said the move is “a massive setback” for struggling retailers.

“In less than eight months from when the Fair Work Commission handed down its decision, and retailers made new plans for the future of their businesses, this hard-fought victory is about to be snatched away from them.”

He said retailers were left facing an uncertain future after that victory was “pulled from under them by a razor edge in for its opponents in the Senate”.

The Senate approved the reversal by just one vote, after outspoken Nationals senator George Christensen crossed the floor to vote in favour of removing the cuts.

“This has been done by those who have chosen to overturn a decision that was made by an organisation created by the Parliament to make fair decisions for the future productivity and prosperity of this country,” said Mr de Bruin.

“This action is difficult to comprehend when a group of politicians cannot accept the decision of the fairly constituted court.”

While the measure narrowly passed the Senate, it was subsequently blocked in the Lower House. At this stage, it is unclear if the bill will be reintroduced at a later stage.